The invention relates to a valve stem extension for extending a valve stem.
A typical prior art valve 10, such as a ball valve or plug valve, is illustrated in FIG. 1. Valve 10 includes a valve body 12 defining an inlet 14 and an outlet 16. A ball or plug (not shown) located within body 12 is movable between a first position which blocks flow through valve 10, and a second position which allows flow through valve 10. Attached to the ball or plug and extending from body 12 is a valve stem 18. A packing nut 19 compresses a teflon seal (not shown) underneath nut 19, forming a seal between valve stem 18 and body 12.
The ball or plug is moved by rotating valve stem 18. Valve stem 18 includes two opposing flat sides 24a, 24b, and two opposing circumferential threaded sides 26a, 26b. A handle 20 attached to valve stem 18 is used to rotate valve stem 18. Handle 20 defines an oblong opening 28 which includes two opposing flat sides 30a, 30b for engaging the opposing flat sides 24a, 24b of valve stem 18. A top nut 32 is threaded onto valve stem 18, threadingly engaging the opposing circumferential threaded sides 26a, 26b of valve stem 18, to secure handle 20 to valve stem 18.
Valve body 12 includes rotation limiting flanges 34a, 34b, which define rotation limiting surfaces 35a, 35b. Handle 20 has a stub 36. Rotation of handle 20 is limited by abutment of stub 36 against rotation limiting surfaces 35a, 35b.